Small businesses in mail order, graphic arts, light manufacturing, etc. require stapling of materials up to 1/2-inch thickness. Hand or foot powered machines are in general use, but these are tedious and slow. Hand operation requires efforts which, after a few hours, are exhausting to many operators, while foot operation requires standing on one foot or the other for long hours while operating a relatively high foot pedal having a relatively long travel distance.
An electric machine is much needed, but existing machines which are in the price range of such businesses are, in the present state of the art, relatively small in size, and are limited to stapling relatively thin materials, due to the small size of the solenoid generally used in low price machines. Since larger solenoids are very expensive, efforts have been made to increase the thickness of work that such small solenoid machines can handle by using very thin staple wire. These thin staples however, are too weak to hold, in many applications, such as book binding, for example.
In addition, adjustment of such machines to various work thicknesses is not generally provided, with the result that the head height clearance may be marginal when used with the maximum thickness that the machine can handle, and this increases the difficulty of getting work into the machine for stapling.
Making such a machine with a solenoid having the size and stroke and force needed to handle 1/2-inch work thicknesses with heavy wire sizes of staples would, in the present state of the art, drastically increase the cost of the machine, due to the much higher cost of the large, long stroke solenoid needed for this work. The price range would then compare with the cost of staple driving machines employing a motor, flywheel and electric clutch combination, which are common in the shoe and belting industry, and which are ordinarily too expensive for general use in schools, small print shops, etc.
Another problem with existing electrically powered staple driving machines results from the fact that in stapling work, the stapling head must be raised a clearance distance above the work to facilitate work flow. Often this distance is enough so that an operator's hand or finger can pass under the stapling head. In existing electrically operated machines of either the solenoid or motor powered type, the power stroke is used to bring the stapling head down to the work as the staple is driven, and thus the power stroke is a constant danger to the operator. As a result, most power staplers are used with various finger guards, which tend to slow the work flow, and cause inaccurate staple placement. Furthermore, operators tend to remove such guards and are then exposed to the danger mentioned.
In an effort to alleviate this problem, some solenoid operated machines have been made in which a foot pedal is used to bring the head down onto the work manually, and then further foot pedal pressure operates the solenoid to drive the staple electrically. This type of machine is safer to operate, but it requires almost the same operator effort as a manual machine, since the operator must essentially stand on one foot while operating it, often for many hours.